Dental articulator



June 7, 1938. c, HAGMAN AL I 2,119,579

DENTAL ART I CULATOR Filed NOV. 21, 1934 Han x C. Hagfman and Alexander S. 'T. Lagdard Patented June 7, 1938 UNITED STATES DENTAL ARTIGULATOR Harry 0. Hagman and Alexander S. '1. Lagaard, Minneapolis, Minn.

Application November 21, 1934, Serial No. 754,0 10

18 Claims.

Our invention relates to dental articulators adapted to support casts or models of human teeth, models of human jaws bearing wax bites, wax trial plates, and sets of artificial teeth for the purpose of construction, study and experiment and has for its object to provide an extremely simple and practical device wherein the occluding and masticating movements of the natural teeth can be reproduced with models or teeth supported in the articulator, so that when construction of a restoration is completed it will function properly in the mouth.

Another object of the invention resides in H providing a dental articulator which is an improvement over the articulator disclosed in Patent No. 1,763,006 issued to Harry C. Hagman November 19, 1929.

A still further object of the invention resides in providing clamping means for locking the swinging model support in any adjusted position.

Another object of the invention resides in providing a key for restraining rotational movement of the swinging model support.

An object of the invention resides in constructing the swinging model support with a stem and in providing means carried by said stem for returning the swinging model support to normal position.

A feature of the invention resides in constructing the frame of the articulator with a socket and in providing a sliding member on the stem of the swinging model support having a conical cam for engagement with said socket and in further providing a spring encircling said sliding member and urging said conical cam into engagement with said socket.

Another object of the invention resides in providing a threaded member extending through the mounting plate and adapted to be engaged by a nut having at its outer end a projecting portion adapted to become imbedded in the jaw model to hold the same in position upon the mounting plate and to further provide a projection on the mounting plate engaging the model for restraining the model from rotation.

A still further object of the invention resides in constructing the swinging arm with a lug and 50 in providing a screw threaded into the upright of the frame-for engagement with said lug to swing said arm and limit the downward movement thereof.

Other objects of the invention reside in the 55 novel combination and arrangement of parts and in the details of construction hereinafter illustrated and/or described.

In the drawing: 7

Fig. 1 is a perspective View of an articulator illustrating an embodiment of our invention.

Fig. 2 is an elevational side View of the structure shown in Fig. 1 with a portion of the same illustrated in section.

Fig. 3 is an elevational sectional view taken on line 33 of Fig. 2. 10

It has been found that the normal surfaces of occlusion of the human teeth coincide with the surface of a sphere approximately six to eight inches in diameter which has its center at a point situated above the roof of the mouth and is intercepted by the longitudinal axes of the teeth. The relative movements of the lower jaw with respect to the upper jaw will be closely reproduced if the upper jaw be assumed to be universally pivoted at the center of said sphere and articulated by swinging it about this center. Our invention embodies the principles of this theory.

Having reference to the drawing and particularly to Fig. 1 it will be noted that the invention proper comprises a frame A in which may be mounted the lower cast or model. This frame has a base 16 from which issues an upright 10 disposed at the rearward portion of the same. To this upright is pivoted by means of a hinge I I a swinging arm l2 which is formed with an overhanging portion l3. A hanger B is suspended from the overhanging portion 13 of arm I2 by means of a ball and socket joint I4 and may carry a mounting plate l5 or other suitable support for the upper jaw model.

For the purpose of illustrating the application of the invention, two complement-a1 jaw -models 11 and 18 have been illustrated which are applied to the mounting plate I5 and the base 16 respectively. These jaw models have restorations 8| and 82 applied to the same which in the particular case illustrated happen to be full dentures. By swinging the arm back and forth upon the hinge H, as shown in Fig. 1, ready access to the models mounted on the base it and the mounting plate l5 may be had. When the models are disposed on said plates, swinging of the hanger B together with the swinging of the arm,l2 on hinge II, as will hereinafter be more fully described, will cause the models to move relative to one another in a manner very closely simulating the movements of the teeth when applied to the jaws of the patient. A

detail description of the construction and operation ofthe invention is as follows.

The frame A of the invention. as previously stated, consists of a base l6 which is in the form of a plate and which is adapted to directly rest upon-the surface on which the articulator is placed. The upright Hi of the frame A issues upwardly from the base I6 at the rearward end of the same and terminates in two hinge leaves i7 and .58 which form part of the hinge The lower'end of arm I2 is provided with a hinge leaf 23 which fits between the two hinge leaves 51 and I8. A pintle 24 passes through the various hinge leaves I1, 23 and I8 and serves to pivotally support the arm |2 with respect to the upright ii. The pintle 24 is held attached to the hinge leaf 23 'by means of a pin key 21 which passes directly through the same and may be riveted in place, if desired. The base l6 serves as .a mounting plate or support for the lower model to be mounted in the articulator .and for this pur- 9 and whichproject outwardly from the surface of the said base. When models are mounted upon the base 16 and cemented thereto through plaster of Paris investment or some other similar substance, the models remain attached to the base until manually disengaged therefrom.

At the upper end of the arm I2 is provided a head 22 which forms part of the ball and socket joint M. This head is constructed wit-ha bore 23 open at the top which is reduced at its lower end to form an opening 3| which, is open at the bottom. This construction provides a seat or shoulder 29 betweensaid opening and'bore which 'seat'e ncircles the opening 3|. V i

The hanger B includes a stem 25 which is secured to a spherical head or ball 26 forming part of the ball and socket joint l4. This ball is received within the bore '28 in the head 22' of frame A. Ball 26 is seated on the seat or shoulder 29 at the lower end of the bore and fits snugly within the bore 28, being held from lateral movement thereby. The stem 25 extends through the opening 3| and is free to swing in any vertical plane, being guided for such movement by said ball and seat.

The lower end of the stem 25 has attached to it the mounting plate l5, previously referred to, which is constructed with .a body portion 32. Issuing upwardly from the center thereof is a boss 33. Boss 33 is drilled as indicated at 34 to receive; the lower end of the stem 25. To hold the mounting plate l5 attached to said stem a set screw 35 is employed which is threaded into the boss 33 and which enters a cavity 36 in the stem 25. By means of this construction the V mounting plate [5 is detachably secured to. the

7 with ribs 90 which serve to hold the-model 11 in place thereon.

The hanger B is'held from rotation by means of a key 31. This key has a threaded shank 38 which is screwed into a' boss 39 formed on the head 22. The end of the key 31 is constructed with a pin 4| which is adapted to be snugly received within .a slot 42 formed in the ball 26. The slot 42 is parallel with the axis of the stem 25 and the pin 4| is radially disposed with respect to the center of the ball 26 and is at right angles to the axis of the stem 25 whenthe hanger B is in normal position. Pin 4| may be; made struction simulates very closely the'movement of 46 away from the ball 26.

slightly tapered so that as the same is screwed into the slot 42, wear occurring through the use of the device may be taken up. A lock nut .43 and a lock washer 44 applied'tothe end of the shank 38 of said key hold the same in adjusted position. By means of this construction the hanger B may swing in anyvertical plane and at the same time rotation of the saidhanger is prevented. The movement procured by this conthe human mandible so that teeth constructed with our improved articulator function in the proper manner when disposed in the patients mouth. r In the construction of dental restorations and in the study of mouth conditions from models" mounted on the articulator it frequently becomes desirable to hold the jaw models in certain rela-v tive positions. For this purpose a clamping de-- vice indicated in its entirety by the reference numeral 45 is employed. This clamping device includes a shoe 46 which snugly slides within the bore 28 of head 22; This shoe is constructed with a conical surface 41 which is adapted to engage the upper portion of the ball 26; When this shoe is forced downwardly, friction is exerted.

between the said shoe and the ball and further friction is produced between the ball and the seat 29. 'Such friction serves to hold the ball from movement and to retain the hanger B in any adjusted position desired. For producing the necessary pressure, a clamp screw 48' is employed:

which is constructed with a knurled head 49 .and

a threaded shank 5i. Shank 5| is screwed into a.

bushing 52 which in turn is threaded and is screwed into threads 53 formed in the upper end of the bore 28 of head-22. addition to supporting. the screw 48, serves as an abutment for limiting the movement of'the shoe This is accomplished The bushing 52 in r by the lower end54 of this bushing which an:

upright I0 is formed a boss 58 which is threaded i to receive the shank 59 of said screw. The end of the screw is provided witha reduced tip 63 which is adapted to engage a lug 55 issuing outwardly from the lowermost portionof leaf 23 of arm l2. It will be noted that the shank 59.01

screw 51 is eccentric with respect to the axis of turned in a clockwise direction lug 56 is rotated and the arm i2 is swung about thehingeil to raise the model support l5 and cause the models to occupy a position similar to the openposition of the human jaws. V The screw 5'! may be held 7 in adjusted position through a lock nut 64 threaded on the shank 5S and engaging the boss 58.

In the use of the articulator, the upper jaw' v model support is normally in a position such" that the jaw models mounted thereon are in nor-.

mal occlusion. When the model support'is swung about the ball and socket joint l4 it is desirable that the same return to normal position. For this purpose a device is employed'which is best shown in Figs. 1, 2 and 3 and which is indicated in its entirety by the reference numeral 65. This device includes a sliding member 86 which comprises a tubular portion 81 slidably 'mounted'on' the upper part of stem 25 "of hanger B; This pintle I4 of hinge so that when the screw is? tubular portion is free at its lower end and is provided at its upper end with a conical cam 58. Cam 68 is adapted to engage a conical socket 69 formed on the underside of the head 22 and concentric with opening 3|. and bore 28. When sliding member 66 is urged toward the head 22, cam 68 moves the stem 25 into alignment with respect to the axis of bore 28 thereby returning the hanger B to normal position. The sliding member 66 is urged toward the head 22 by means of a compression coil spring which is seated at one end against a shoulder H formed on the tubular portion 61. This spring is further seated at its other end against a collar 12 secured to the stem 25 immediately above the boss 33 of mounting plate l5. Collar 12 is held in position through a pin 13 which extends through said stem and which is received in a recess '14 in the lowermost portion of said collar. The spring 10 is covered by a sleeve 15 which is attached at one end to the tubular portion 6'! of member 66 inproximity to the cam 28. This sleeve at its other end slides upon the collar 12. It will readily become apparent when the hanger O B is swung from its position shown in full lines in Fig. 2 to its position shown in dotted lines that the cam 68 rides along the surface of the socket 69 and that the sliding member 61 is slid along the stem 25 in opposition to the action of the spring Ill. The relation of the parts when the hanger is disposed at its extreme position is illustrated in dotted lines in said figure. When the hanger B is released, spring 10 causes the sliding member 66 to assume its normal position which action moves the hanger back into normal position.

To permit of replacing jaw models upon the articulator after the same have been once removed, we utilize retaining devices which are shown in detail in Fig. 2. One of these retaining devices is used with the base l6 and the other with the mounting plate I5. Inasmuch as both of these retaining devices are identical in construction only the retaining device used in conjunction with base IE will be described in detail. This device comprises a screw 83 which has a threaded shank 85 and a conical head 84. The shank 85 extends through and projects up above the upper surf-ace of the base 16 while the head 84 is countersunk in said base. Screwed upon the shank 85 of said screw is a nut 86. This nut is constructed with an hexagonal portion 81 at the outer end of the same and with a circular por tion 88 adjacent the base l6. Circular portion 88 is smaller in diameter than the hexagonal portion 87 so that projections are formed on the outer end of the nut which become imbedded in undercuts in the jaw model 11 and which hold the model firmly attached to the base.

When it is desired to remove the jaw model 18 mounted on the base I6, the screw 83 is first removed. A sharp instrument is then inserted between the jaw model and the base [6 and the entire jaw model pried loose from its support. Other models may then be attached to the support and other cases handled on the articulator. When it becomes desirable to reapply the model the same is merely placed upon the base I6 with the grooves formed in the bottom of the same registering with ribs l9 and 2 of the base. Screw 83 is again screwed into the nut 8'! and the model is as firmly attached to the support as in the original instance. The same procedure is utilized in the removing andreplacing of the jaw model 17.

In the use of our invention the models are mounted on the articulator in accordance with the customary practice. Where a finder such as disclosed in the patent above referred to is employed, the lower jaw model is placed with the teeth in occlusion with the spherical surface of such finder. Plaster of Paris or some other suitable investment is then placed between the jaw model and the base l6 and allowed to set, which causes the model to be firmly attached to the base. The upper model is then placed in occlusion with the lower model and the same similarly attached to the plate 15. Where insufficient teeth exist on the models, wax replicas may be used to guide the technician in the proper mounting of the models. Where wax bites are available the wax bites can be placed upon the teeth in the lower model and the upper model set into the depression formed on the wax bite. The models may then be attached in position as described. In the use of the articulator the procedure is the same as with any other articulator. In the study of the cases and in the construction of restorations the hanger B may be manipulated to cause the models to move in a manner simulating the movements of the human mandible so that cases may be studied and restorations articulated and caused to function in the proper manner.

Our invention is highly advantageous in that an extremely simple and practical device is provided which reproduces movements of the human mandible with great accuracy. The device is small and can be constructed light so that the same may be easily handled and manipulated. The device for returning the hanger to normal position is positive in action and extremely simple in construction. But a small amount of effort is required to swing the hanger about its pivot and when released returns immediately to normal position. With our construction the hangers will always return to identically the same position so that inaccuracies frequently present in other forms of articulators are entirely eliminated. By means of the retaining device models may be easily detached and replaced whenever desired.

Where it is desirable to study the jaws in positions other than normal occlusion, the clamping device may be used which holds the hanger in any desired position. Our articulator can be constructed at a nominal cost and will not readily get out of order. Adjustment of parts of the invention may be made to take up wear thereby insuring long life.

Changes in the specific form of our invention, as herein disclosed, may be made within the scope. of what is claimed without departing from the spirit of our invention.

Having described our invention, what we claim as new and desire to protect by Letters Patent is:

1. In an articulator, a frame having an arm, a head formed on said arm, a hanger pivoted to said head for swinging movement away from a predetermined position, said hanger including a depending stem, 21. member slidable on said stem, a cam on said member, means on said head for engagement with said cam to cause said hanger to swing back to said position upon sliding movement of said member in one direction, and a spring for urging said cam into engagement with said means to procure movement of said member in said direction.

2. In an articulator, a frame having an arm, a head formed on said arm, a hanger pivoted to said head for swinging movement away froma predetermined position, said ,hanger including, a

ldepending stem, a tubular member. encircling said stem and slidable relative thereto, a conical 'po'rtion encircling said stem, said member being 'slidable relative to said stem, a conical'cam on the'end of said tubular portion nearest said head, aconical socket in said head'adapted to beengaged by said cam, a shoulder on said member near said head, a collar on said stem spaced from the other, end of the tubular portion of' said member and a. compression coil spring encircling the tubular portion of said member and stem and seated at oneendagainst said shoulder'and at its other end against said collar for urging said cam intosaid socket; a i e collar at the other end, said sleeve encircling said A; In an articulator, a frame having an arm,

a head formed on said arm, a hanger pivoted to said, head for: swinging movement away-from a predetermined position, said hanger including a ,f 7 depending stem, a member including a tubular portion encirclingsaid stein, said member being slidable relativeto said stem, a conical cam on the end of said'tubular portion nearest said head, a conical socket in said head adapted to be engaged by said cam,'a shoulder on saidimember near said head, a collar on said stem spaced from the other end of the tubular portion ofsaid member,. a compression coilspring encircling the tubular portion of said member and stem and seated at one end against said shoulder and at its other end against said collar for urging said caminto said pocket, and a sleeve attached to said member at one end and sliding on said spring and covering the same. i

5.'In 'an articulator, a frame having an arm, a head formed on said arm, said head having a bore therein terminating in an annular seat, a

hanger including a ball, disposed within said boreand seated upon said seat, a stem extending from said ball, a shoe within said bore slidable V toward'said ball, a bushing screwed into said head at the open end of the bore and engaging said shoe for limiting the movement of said shoe away from said ball and a screw threaded into said bushing and engaging said shoe, said screw urging the shoe into engagement with said ball and the ball into engagement with said seat.

6. In an articulator, a frame'having a support for a lower jaw model, an arm pivoted to said frame and overreachingamodel carried by said support, said arm terminating at itsouter end in a head, said head having a bore extending therethrough, the bore being vertical when the arm is in normal position, said head being provided at thelower end of the bore with an annular seat fixed relative to the head, a hanger including a ball disposed within said bore and seated upon 'the seat, a stem depending from said ball, a

support for an upper jaw model carried by said stem, a shoe within said bore-slidable toward said ball, said bore being threaded at itsupper end, a bushing threaded upon the exterior and screwed into the threaded end' of the bore, said bushing engaging the end of the shoe and limiting the m ovement of theball away from the seat,

means for holding the bushing in adjusted position relative to the bore, said bushing having a threaded bore therein and a screw screwed into the threaded bore of the'bushing and engaging the'shoe for urging the ballagainst said seat,

'7. In an articulator, a frame, a support thereon .ior a lowerjawmodel, an arm carried byzsaid frame, a head formed on said arm, :and overreaching a jaw model mounted on the support, a hanger pivoted to said head, said hanger including a depending stem and swingable laterally with respect to said jaw model, a support for an upper jawlmodel carried by, said stem, a member car-.

ing a depending stem and swingable laterally' I hanger pivoted to said head, said hanger include,

with respect to said jaw model, a support for an upper jaw model :carried'by said stem, a coil spring encircling saidstem, and means operated thereby for swinging the the lower jaw model.

hanger transversely of 9. In an articulator, aframe, a support there- 'on for a lower jawmodel, an arm carried by said 7 frame, a head formed on said arm, and overreaching a jaw model mounted on the support, a hanger pivoted to said head, said hanger including a depending stem and swingable laterally with respect to said jaw model, a support for an upper jaw model carried by said stem, a member carried by said stem and movablerelative thereto, cam means betweensaid head and member, said cam means operating to procure lateral swingingvmovement of the hanger upon 'movement of said member.

10. In an articulator, a frame, a'support thereon for a lower jaw model, an arm carried by said frame, a head formed on said arm, and overreaching a'jaw model mounted on the support, a hanger pivoted to said head, said hanger including a depending stem, a support for an upper jaw model carried by said stem, said hanger upper jaw model to move laterally in any'direce, tion away from its centric position relative to the lower jaw model, and centering means movably carried by said stem and engaging said head for moving the upper jaw model from any of its lateral positions back to centric position. 11. In an 'articulator, a frame, a support thereon for a lower jaw model, an arm carried by said frame; a head formed on said arm, and over! reaching a jaw model mounted on the support, a hanger pivoted'to said head, said hanger inbeing adapted to swing in a manner to cause the cluding a depending stem, a support for an up,

per jaw model carried by said stem, said hanger beingadapted to swing in a manner tocause the upper jaw model to movelaterally in any direction away from'its centric position relative to. the lower jaw model, and centering means slidable along said stem and engaging said head for 'moving the upper jawmodel from any of its lat reaching a jaw model mounted on the support,

a hanger pivotedtosaidhead, said .hangerin eluding a depending stem, a support for an upper jaw model carried by said stem, said hanger being adapted to swing in a manner to cause the upper jaw model to move laterally in any direction away from its centric position relative to the lower jaw model, a member slidable along said stem and toward said head, said member and head having juxtaposed parts, cam means formed on said parts for cooperation to procure movement of the upper jaw model from any of its lateral positions back to centric position upon movement of said member toward said head, and a spring encircling said stem and urging said member toward said head.

13. In an articulator, a frame having a support for a lower jaw model, an arm pivoted to said frame, said arm terminating at its outer end in a head, said head having a bore extending therethrough, said head being provided at one end of the bore with an annular seat fixed relative to the head, upper jaw model supporting means including a ball disposed within said bore and seated upon the seat, a stem issuing from said ball, a support for an upper jaw model carried by said stem, a shoe within said bore slidable toward said ball, said bore being threaded at its upper end, a bushing threaded upon the exterior and screwed into the threaded end of the bore, said bushing engaging the end of the shoe and limiting the movement of the ball away from the seat, means for holding the bushing in adjusted position relative to the bore, said bushing having a threaded bore therein and a screw screwed into the threaded bore of the bushing and engaging the shoe for urging the ball against said seat.

14. In an articulator, a frame, a support thereon for a lower jaw model, an arm carried by said frame, a head formed on said arm, a stem pivoted to said head and swingable laterally with respect to said jaw model, a support for an upper jaw model carried by said stem, a member carried by said stem and movable relative thereto, and cam means between said head and member, said cam means operating to procure lateral swinging movement of the stem upon movement of said member.

15. In an articulator, a frame, a support thereon for a lower jaw model, an arm carried by said frame, a head formed on said arm, a stem pivoted to said head, a support for an upper jaw model carried by said stem, said stem being adapted to swing in a manner to cause the upper jaw model to move laterally in any direction away from its centric position relative to the lower jaw model, and centering means movably carried by said stem and engaging said head for moving the upper jaw model from any of, its lateral positions back to centric position.

16. In an articulator, a frame, a support thereon for a lower jaw model, an arm carried by said frame, a head formed on said. arm, a stem pivoted to said head, a support for an upper jaw model carried by said stem, said stem being adapted to swing in a manner to cause the upper jaw model to move laterally in any direction away from its centric position relative to the lower jaw model, and centering means slidable along said stem and engaging said head for moving the upper jaw model from any of its lateral positions back to centric position.

1'7. In an articulator, a frame, a support thereon for a lower jaw model, an arm carried by said frame, a head formed on said arm, a stem pivoted to said head, a support for an upper jaw model carried by said stem, said stem being adapted to swing in a manner to cause the upper jaw model to move laterally in any direction away from its centric position relative to the lower jaw model, a member slidable along said stem and toward said head, said member and head having juxtaposed parts, cam means formed on said parts for cooperation to procure movement of the upper jaw model from any of its lateral positions back to centric position upon movement of said member toward said head, and a spring encircling said stem and urging said member toward said head.

18. In an articulator, a frame, a support thereon for a lower jaw model, an arm carried by said frame, a head formed on said arm, a stem, pivot means at one end of said stem for pivotaly sup porting said stem relative to said head, said stem being swingable laterally with respect to said jaw model, a support for an upper jaw model carried by the other end of said stem, a member carried by said stem intermediate the ends therer converting sliding movement of said member into' lateral swinging movement of said stem.

HARRY C. HAGMAN. ALEXANDER S. T. LAGAARD. 

